Cyclin D3 Is a Cofactor of Retinoic Acid Receptors, Modulating Their Activity in the Presence of Cellular Retinoic Acid-binding Protein II

Gilles Despouy,Jean-Noël Bastie,Sylvie Deshaies,Nicole Balitrand,Alexandra Mazharian,Cécile Rochette-Egly,Christine Chomienne,Laurent Delva

doi:10.1074/jbc.m210697200

Abstract

Ligand-induced transcription activation of retinoic acid (RA) target genes by nuclear receptors (retinoic acid (RAR) and retinoid X (RXR) receptors) depends on the recruitment of coactivators. We have previously demonstrated that the small 15-kDa cellular RA-binding protein II (CRABPII) is a coactivator present in the RA-dependent nuclear complex. As identifying cell-specific partners of CRABPII might help to understand the novel control of RA signaling, we performed a yeast two-hybrid screen of a hematopoietic HL-60 cDNA library using human CRABPII as bait and have subsequently identified human cyclin D3 as a partner of CRABPII. Cyclin D3 interacted with CRABPII in a ligand-independent manner and equally bound RAR alpha, but not RXR alpha, and only in the presence of RA. We further show that cyclin D3 positively modulated RA-mediated transcription through CRABPII. Therefore, cyclin D3 may be part of a ternary complex with CRABPII and RAR. Finally, we show that cyclin D3 expression paralleled HL-60 differentiation and arrest of cell growth. These findings led us to speculate that control of cell proliferation during induction of differentiation may directly involve, at the transcriptional level, nuclear receptors, coactivators, and proteins of the cell cycle in a cell- and nuclear receptor-specific manner.

Highlights

Retinoic acid (RA)1 plays a pivotal role in the development and homeostasis of vertebrates through its ability to directly control the transcription of target genes involved in the control of cell proliferation, differentiation, and survival
We previously showed that a small protein (15 kDa) belonging to the family of intracellular lipid-binding proteins that bind small hydrophobic molecules such as retinoids and fatty acids [9], cellular retinoic acid-binding protein II (CRABPII), acts as a coactivator of nuclear retinoid receptors [10]
Identification of Cyclin D3 as a CRABPII-binding Protein in Yeast Two-hybrid Screening—The yeast two-hybrid system was used to identify proteins that interact with hCRABPII

Summary

Introduction

Retinoic acid (RA)1 plays a pivotal role in the development and homeostasis of vertebrates through its ability to directly control the transcription of target genes involved in the control of cell proliferation, differentiation, and survival. Our results identify cyclin D3 as a partner of a ternary complex with the coactivator CRABPII and the nuclear receptor RAR␣ and demonstrate another level of transcriptional control during RA-induced differentiation and arrest of cell growth. HL-60 cells were electroporated, as previously described [10], with the luciferase reporter gene (hRAR␤2-luciferase) in the presence or absence of the expression vectors for cyclin D or CRABPII.

Results

Conclusion